Signing and sending PDFs via email is always a pain, especially if you think you need to print it, sign it, scan it, and email it back to someone in a timely manner. But you don't! Using a few apps and built-in software, you can save time, money, and the agony of finding and printing from the correct office printer.

Writing an email isn't so hard, but figuring out how to sign off can be a real challenge. Is 'cheers' too casual? Too pretentious? Too British? Is 'sincerely' timeless and professional, or stodgy and overly formal? We consulted business experts to help list out 26 email sign-offs you should probably avoid.

iOS: We've talked about signing documents from your phone before, but one of the lesser celebrated features of iOS 9 was integrating this directly into the Mail app.

Dear Lifehacker, My company has work-from-home employees, directors and contractors spread throughout Australia. When we have a document that requires multiple signatures, I ask each person to sign, scan and email their own copy back to me. Common sense would suggest that the collection of each of these individually signed (but otherwise identical) documents equals one fully signed document. But what does the law say about this, if anything? And is there a better way to do this? Thanks, Signing Off

Depending on who you ask, a mobile signature in email is either a clever time-saving trick... or just plain annoying. Which side of the fence are you on?

Dear Lifehacker, I'm tired of printing out a document and scanning it back in just to put my signature on it. Is there a better way to do this? I know there are a lot of apps out there, but there are so many I don't even know where to start.

Back in the 1990s when email signatures first became popular, they received a bit of a backlash when senders starting abusing their "email powers" and added too many graphics, their own favourite quotations and the dreaded, Comic Sans font (sometimes in multiple colours!). An email signature should be considered a good thing. But it needs to look professional and the content must be in moderation or serve a purpose. Here are six good reasons to use an email signature.

The default action of just about every smartphone email application is to append a signature at the bottom telling recipients not only what type of phone you've sent it from, but often the network you're using. It's annoying, it looks unprofessional and it's often a secret to you until you send your first mail. Here's how to wipe it out.

Chrome: Technology has somehow made signing paperwork more annoying than it used to be. Now you have to print something out, sign it and scan it back in if you want to email it. HelloSign adds digital signatures to Gmail, so you can sign a document without even leaving your inbox.

Dear Lifehacker, I'm trying to find software that could be used in conjunction with Dropbox or other features to allow people to put a signature on a document and email it back or otherwise. I'm trying to cut back on paper and hug some trees! Any suggestions? Thanks, Signing Up

iOS 5 still officially lacks support for multiple email signatures. If you've got more than one email account on your iPhone or iPad, then Lifehacker reader Ned Smith has provided a dynamite tip for creating multiple email sigs

New web service Protocol.by helps you generate email signatures that link to your account at the service, and that contain the information your email recipients need to best contact you, and the order in which they should try.

Chrome/Firefox: The Blank Canvas Signatures for Gmail extension helps you manage multiple email signatures — with support for HTML formatting and even across multiple email addresses, so you can have a different signature for each address you use with Gmail.

Adding a scanned signature to a document is the easiest way to sign it. Tech blogger Helen Bradley explains how you can add your signature to the clip art collection in Word 2010, making access to your signature a simple search away.

One of the things lacking from iOS's built-in Mail application is HTML signatures. Free web app iPhone Signature Creator, however, helps you create a home screen shortcut to send messages with signatures containing links and images.

Google has rolled out rich text signature support to Gmail so you can have a fancy signature without any Greasemonkey scripts or Macgyver-like cobbling together of Google Labs features.

Email signatures might be more annoying than you think, but we all experience plenty more gaffes, annoyances and misfires in our inbox. We asked our savvy readers to share their biggest email annoyances, and here's what they said.

Smart phones are invariably configured to add a "Sent from my iPhone" or "Sent from my BlackBerry" signature. While their presence often reflects users who can't be bothered (or don't how) to change default settings, they can also convey a dismissive attitude to the recipient.

newVideoPlayer( {"type":"video","player":"http://www.youtube.com/v/pXh6sRRWbrw&hl=en&fs=1&fmt=22","customParams": ,"width":570,"height":412,"ratio":0.824,"flashData":"","embedName":null,"objectId":null,"noEmbed":false,"source":"youtube"} );

Thanks to some handy tricks in the Google Labs bag you can easily add an HTML signature complete with images and save it for future use without plugins or outside help.